Benzimidazole derivatives intended for inhibiting gastric acid secretion are disclosed in numerous patent documents. Among these can be mentioned GB No. 1 500 043, GB No. 1 525 958, U.S. Pat. No. 4,182,766, U.S. Pat. No. 4,255,431, U.S. Pat. No. 4,599,347, U.S. Pat. No. 4,555,518, U.S. Pat. No. 4,727,150, U.S. Pat. No. 4,628,098, EP No. 124 495, EP No. 208 452, EP No. 221 041, EP No. 279 149, EP No. 176 308 and Derwent abstract No. 87-294449/42. Benzimidazole derivatives proposed for use in the treatment or prevention of special gastrointestinal inflammatory diseases are disclosed in U.S. Pat. No. 4 539 465.